Composition Effect on the Formation of Oxide Phases by Thermal Decomposition of CuNiM(III) Layered Double Hydroxides with M(III) = Al, Fe.

The thermal decomposition processes of coprecipitated Cu-Ni-Al and Cu-Ni-Fe hydroxides and the formation of the mixed oxide phases were followed by thermogravimetry and derivative thermogravimetry analysis (TG - DTG) and in situ X-ray diffraction (XRD) in a temperature range from 25 to 800 °C. The as-prepared samples exhibited layered double hydroxide (LDH) with a rhombohedral structure for the Ni-richer Al- and Fe-bearing LDHs and a monoclinic structure for the CuAl LDH. Direct precipitation of CuO was also observed for the Cu-richest Fe-bearing samples. After the collapse of the LDHs, dehydration, dehydroxylation, and decarbonation occurred with an overlapping of these events to an extent, depending on the structure and composition, being more pronounced for the Fe-bearing rhombohedral LDHs and the monoclinic LDH. The Fe-bearing amorphous phases showed higher reactivity than the Al-bearing ones toward the crystallization of the mixed oxide phases. This reactivity was improved as the amount of embedded divalent cations increased. Moreover, the influence of copper was effective at a lower content than that of nickel.

Triazole-based highly selective supramolecular sensor for the detection of diclofenac in real samples.

A triazole-based supramolecular chemosensor 6 for the selective spectrophotometric detection of diclofenac in human plasma and tap water was developed. The 6 was synthesized through click approach and characterized via UV-vis spectroscopy, FT-IR, Mass and NMR spectroscopy. The supramolecular interaction of compound 6 with commonly used drugs has been investigated with the help of UV-vis spectral titrations, FT-IR and (1)H, (13)C NMR spectroscopy. The UV-visible spectral changes upon addition of various commonly used drugs showed that compound 6 is highly selective for diclofenac over other drugs. The supramolecule 6 exhibited a selective enhancement in the absorbance intensity after mixing with diclofenac in human plasma and water samples in the presence of other drugs at pH 6-7, with a linear range of 0.938 (R(2)=0.938) and a limit of detection 10µM. The relative standard deviation (RSD) for 100µM diclofenac was found to be 0.462. The Job's plot analysis revealed that diclofenac bind to compound 6 in 1:1 stoichiometry.